The Muslim Brotherhood is the best-organised political movement in the most influential country in the Arab world. But what do they do next?
The Muslim Brotherhood tells ITV News they are against violence but will "pay the price of their blood" to restore their ousted president.
Egypt's army has named two further officials in the transitional government as its supporters and opponents vowed to stay on the streets.
European Union foreign policy chief Cathy Ashton has met ousted Egyptian president Mohamed Morsi and held two hours of "in depth" discussions with him, her spokeswoman, Maja Kocijancic, said.
Supporters of Egypt's ousted president Mohammed Morsi marched towards security headquarters in Cairo on Monday night, raising fears of new clashes as the EU's foreign policy chief met local officials, according to the Agence France Presse agency.
The marches came despite a warning from the National Defence Council late Sunday that it would take "decisive and firm action" against demonstrators if they went beyond their right to peaceful protest.
The Egyptian authorities have ordered that deposed president Mohamed Morsi be detained for 15 days over an accusation he conspired with Hamas in a series of prison breaks in Egypt in 2011, Reuters have reported.
Seven people were killed and 261 wounded in Cairo when supporters of Mohamed Morsi clashed with the deposed president's opponents and security forces overnight, the head of Egypt's emergency services said.
Mohamed Sultan told Reuters two people had been killed at a bridge in central Cairo and five more in the capital's Giza district.
Police fired tear gas in central Cairo last night when protesters calling for the reinstatement of the ousted Islamist president, Mohamed Morsi, scuffled with drivers and passers-by annoyed that they had blocked major roads.
Supporters of Morsi, Egypt's first freely elected president, threw rocks at police near Ramses Street, one of the capital's main thoroughfares, and on the Sixth of October Bridge over the Nile in the first outbreak of violence in Egypt in a week.
Egyptian security forces fired tear gas in central Cairo after scuffles broke out between supporters of ousted Islamist president Mohamed Morsi and locals in the area of Ramses Street, eye witnesses said.
It was the first violent confrontation involving pro-Morsi protesters for a week. Last Monday, 53 pro-Morsi demonstrators were killed outside the Republican Guard compound in Cairo. Four soldiers also died in the clash.
The United States has called for the release of ousted Egyptian president Mohamed Morsi, who has been held in custody by the army since last week.
Thousands of Muslim Brotherhood supporters today took to the streets of Cairo to demand Morsi's reinstatement.
ITV News Middle East Correspondent John Ray reports.
The US State Department has called on Egypt to release the deposed president Mohamed Morsi from detention, Reuters reports.
Germany's Foreign Ministry has urged all political parties in Egypt to refrain from violence or threats of violence, and called on Egyptian authorities to allow an international organisation access to ousted Islamist president Mohamed Morsi. A ministry spokesman said:
All forms of political persecution would be extremely damaging for the future of Egypt.
We call for an end to the restrictions on Mr Morsi, and we also urge all political powers, in particular the leaders of the Muslim Brotherhood, to refrain from all forms of violence or threat of violence